Java getter、setter、构造函数及其参数_Java_Constructor_Setter_Getter

Java getter、setter、构造函数及其参数

java

Java getter、setter、构造函数及其参数,java,constructor,setter,getter,Java,Constructor,Setter,Getter,到目前为止，你帮了我很大的忙，尽管我的问题措辞不太好。我想我几乎知道我在做什么，但我正试图弄清楚能手、二传手和建设者之间的关系。我有两门课，如下所示 Student和Name我对getter和setter中的参数与构造函数之间的关系感到困惑如果我从名称构造函数中删除参数，即 public Name (){ this.firstName = firstName; this.lastName = lastName; 并且还编辑了学生构造函数来反映这一点 public Student(int id

到目前为止，你帮了我很大的忙，尽管我的问题措辞不太好。我想我几乎知道我在做什么，但我正试图弄清楚能手、二传手和建设者之间的关系。我有两门课，如下所示

Student

和

Name

我对getter和setter中的参数与构造函数之间的关系感到困惑

如果我从名称构造函数中删除参数，即

public Name (){
this.firstName = firstName;
this.lastName = lastName;

并且还编辑了学生构造函数来反映这一点

public Student(int id, String firstName, String lastName, String street, String area, String city, String country, int age, char gender, String college, String course,  int level, int gradePointAverage){ //This is the list of variables called from the Student class
this.id = id;
this.name = new Name(); //I have removed the parameters here
this.name.setFirstName(firstName);
this.name.setLastName(lastName);
this.address = new Address(street, area, city, country);
this.age = age;
this.gender = gender;
this.college = college;
this.course = course;
this.level = level;
this.gradePointAverage = gradePointAverage;

}

我不确定这会有什么影响。如果有人能向我解释我在哪里应该/不应该有参数以及为什么，我将不胜感激？理解这个概念是目前阻碍我进一步进行编码的原因

public class Student {
    private Name name; // This is calling from the Name class, giving it the name 'name'
    private Address address; // This calls from Address, giving it the name 'address'

    private char gender;

    private String course, college;

    private int gradePointAverage, id, age, level;

    public Student(int id, String firstName, String lastName, String street, String area, String city, String country, int age, char gender, String college, String course,  int level, int gradePointAverage){ //This is the list of variables called from the Student class
        this.id = id;
        this.name = new Name(firstName, lastName);
        //this.name = new Name();
        this.name.setFirstName(firstName);
        this.name.setLastName(lastName);
        this.address = new Address(street, area, city, country);
        this.age = age;
        this.gender = gender;
        this.college = college;
        this.course = course;
        this.level = level;
        this.gradePointAverage = gradePointAverage;
    }

    public int getId(){
        return id;
    }

    public String getName(){
        return name.toString();
    }

    public String getAddress(){
        return address.toString();
    }

    public int getAge(){
        return age;
    }

    public char getGender(){
        return gender;
    }

    public String getCollege(){
        return college;
    }

    public int getLevel() {
        return level;
    }

     public String getCourse() {
        return course;
    }

    public int getGradePointAverage() {
        return gradePointAverage;
    }

    public void printStudent() {
        System.out.println("The Student " + name.toString() + " is logged under the student ID number " + id + ".");
        System.out.println("They live at " + address.toString() + " and their age is " + age + ".");
        System.out.println("Their gender is " + gender + ".");
        System.out.println("The student studies at " + college + " attending classes in " + course + ".");
        System.out.println("Their level is " + level + " and the student grade average in points is " + gradePointAverage + ".");
        System.out.println();
    }

}

和

Name

public class Name{

private String firstName, lastName;

public Name (String firstName, String lastName){
//public Name (){
    this.firstName = firstName;
    this.lastName = lastName;
}

public void setFirstName(String firstName){
    this.firstName = firstName;
}

public void setLastName(String lastName){
    this.lastName = lastName;
}

//public String getFirstName() {
//  return firstName;
//}

//public String getLastName() {
//  return lastName;
//}

///** Returns first name concatenated to last name */
//public String toString() {
//  return firstName + " " + lastName;
//}

}

构造函数

用于初始化对象实例，以确保在创建时提供

有效

对象状态所需的所有最小数据量

在您的情况下，

Name

应该有一个

constructor

，它需要

firstName

和

lastName

，因为正是这些东西使

Name

对象完全初始化。此对象的工作方式应该与您显示的

地址

对象相同

否则，如果使用

setXXX

方法，

名称

对象不完整，两个

字符串

对象初始化为

null

或其他一些未定义的状态。

构造函数用于初始化对象实例，以确保在创建时间